Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02800042 2012-12-19
50621-9D1
SEALER FOR TEST SAMPLE DEVICES
This application is a divisional of Canadian National Phase Patent Application
Serial Number
2,535,155 filed August 13,2004.
BACKGROUND OF THE INVENTION
Field of the invention
This invention relates to devices and related instruments and systems that
test biological,
microbiological, chemical or other types of samples. The invention in
particular relates to a
sealer assembly for sealing test sample devices that are supplied with a fluid
sample via a=
transfer tube.
Description of related art
Biological samples can be reacted and subjected to chemical or optical
analysis using
_ 15
various techniques, including transmittance and/or fluorescence optical
analysis. The purpose of
the analysis may be to identify an unknown biological agent or target in the
sample, to determine
the concentration of a substance in the sample, or determine whether the
biological agent is
susceptible to certain antibiotics, as well as the concentration of
antibiotics that would be
effective in treating an infection caused by the agent.
In the mid-to late 1970's, engineers and scientists working with the
applicants' assignee
and its predecessor in interest developed a technique for conducting ciptical
analysis of biological
samples using a sealed test sample card containing a plurality of small sample
wells. The
technique, and related instruments and devices, came to be known in the
industry as the "Vitek
System". The Vitek System was (and continues to be) a commercial success.
The cards used in the Vitek 'System are known in the patent literature, see
e.g., U.S.
Patents 4,118,280, 3,963,355, 4,018,65; 4,116,775 and 4,038,151. More recent
versions of the
cards are described in U.S. Patents Des, 382,647, Des, 414,272, 5,609,828,
5,746,980, 5,766,553,
5,843,380, 5,869,005, 5,916,812, 5,932,177, 5,951,952, and 6,045,758.
,
CA 02800042 2012-12-19
56621- 9D 1
Cards were developed for both identification of unknown microorganisms that
may be
present in a sample and susceptibility of a known organism to precisely
calibrated concentrations
of antibiotics. During manufacture of the cards, the wells are filled with
either various types of
growth media for various biological agents, or else concentrations of
different antibiotics, and
covered with a transparent sealing tape.
The cards have an external transfer tube port as a mechanism for allowing a
fluid sample
to enter the card. The cards further include an internal fluid passageway
structure for allowing
fluid to enter the wells of the card from the transfer tube port. One end of
straw-like transfer
tube is inserted into the transfer tube port. The other end is inserted into
an open receptacle (e.g.,
test tube) containing the fluid sample to be tested, In accordance with the
teaching of the prior
art Charles et al. patent, U.S. Patent No. 4,188,280, the card with attached
transfer tube and test
tube are placed into a stand-alone vacuum and filling sealing machine, known
as the Vitek '
Filler Sealer. The filling and sealing machine generates a vacuum. When the
vacuum is released,
the fluid sample is drawn from the test tube into the transfer tube and
through the internal
channels of the card and into all of the sample wells. In the instrument of
the prior art Charles et
at. '280 patent, after the wells of the card are loaded with the sample, the
cards are manually
inserted into a slot in a sealer module in the machine, where the transfer
tube is cut and melted,
sealing the interior of the card.
The cards are then manually removed from the filler/sealer module and loaded
into a
reading and incubating machine, known as the Vitek Reader, also described in
the Charles et
al. '280 patent. The reading and incubating machine incubates the cards at a
desired
temperature. An optical reader is provided for conducting transmittance
testing of the wells of
the card. Basically, the cards are stacked in columns in the reading machine,
and an optical
2
CA 02800042 2012-12-19
56621-9D1
system moves up and down the column of cards, pulling the cards into the
transmittance optics
one at a time, reading the cards, and placing the cards back in the column of
cards.
The arrangement of the early Vitek System (as described in the Charles et al.
'280 patent)
has several limitations, in that two machines, a filler/sealer and a reader,
are required to process
and analyze the cards. Furthermore, additional time and labor are required to
conduct the
complete analysis of the card. The applicants' assignee later developed and
commercialized a
fully automated instrument, referred to herein and known in the art as the
"Vitek 2" instrument.
The Vitek 2 instrument automates both the vacuum loading and sealing
operations and combined
them with incubation and reading in a single instrument.
Briefly, the "Vitek 2" system provides an automated sample testing machine
that
performs dilutions for susceptibility testing, fills the cards with the
samples at a vacuum station,
and seals the card by cutting the transfer tube, and conducts incubation and
optical transmittance
and fluorescence analysis of the cards, all automatically. The machine
provides for novel
pipetting and diluting stations, permitting fluids to be added to the test
tubes or transferred from
one test tube to another. The machine is capable of conducting simultaneous
susceptibility and
identification testing of a sample placed in a single test tube. The machine
provides for rapid,
automatic identification and susceptibility testing of the sample.
The instrument uses a sample tray or "boat" and a test sample positioning or
transportation system that moves the "boat" in four separate paths around a
rectangular base pan
among the various stations. The user places a cassette loaded with cards and
test tubes containing
samples into the boat at a loading station. The design of the positioning
system is such that it
permits essentially a custom configuration of stations above the base pan.
Expansion of the
3
CA 02800042 2014-12-08
50621-9D1
machine to include additional carousels and reading stations, or addition
types in intermediate
procession stations such as dilution stations or vacuum stations, can be
readily accomplished.
The overall instrument is described in several patents, including
U.S. Patents 5,762,873 and 6,086,824. The cutting and sealing station that
cuts the transfer
tubes to seal the cards is described in U.S. Patent 5,891,396, particularly in
Figures 1, 4 and 5
thereof and at columns 15 and 16 thereof.
Various aspects of the present invention provide an improvement to the sealing
arrangement described in U.S. Patent 5,891,396. In particular, the present
arrangements
provide for easier and more accurate alignment of the sealer to the test
devices and transfer
1 0 tubes, a preloading feature that allows for cutting of the transfer
tubes with tighter tolerances,
and safety features that prevent inadvertent touching of the hot cutting wire.
4
CA 02800042 2012-12-19
50621-9D1
SUMMARY OF THE INVENTION
In a first aspect, a safety feature is provided for a sealer that involves the
design of an
enclosure for the sealer and a retractable shield that prevents inadvertent
user contact with the
cutting assembly. In particular, a sealer for cutting and sealing a conduit
connecting a test
sample device to a fluid receptacle containing a fluid sample is provided. The
sealer includes an
enclosure having an aperture and shield moveable between a first position
covering the aperture
and a second, retracted position. The sealer includes a moveable cutting
element assembly (e.g.,
heated wire and associated structures) that has a home position located within
enclosure. The
sealer further includes a motor for moving the cutting element assembly
through the aperture to a
deployed position, in which the cutting element assembly is positioned
external to the enclosure
at a position for cutting the conduit. The action of movement of the cutting
element assembly
through the aperture causes the shield to move to the retracted position.
Furthermore, the action
of movement of the cutting assembly from the deployed position to the home
position causes the
shield to retract to the first position covering the aperture. Accordingly,
when the cutting
element is in the home position the shield and the enclosure prevent
inadvertent contact with the
cutting assembly.
In a second aspect, a sealer is designed such that the cutting of the fluid
conduit (transfer
tube) is controlled more precisely. This is achieved by a spring loaded member
or "shoe" and
corresponding fixed structure in the instrument that, together, hold the test
sample device in
position and prevent lateral movement while the cutting element cuts through
the transfer tube.
In this embodiment, the sealer is installed in an automated sample testing
instrument. The
moveable cutting element assembly has a home position and a deployed position.
The cutting
element assembly comprises a cutting wire and the spring-loaded member or
"shoe". The shoe
5
CA 02800042 2013-09-26
50621-9D1
engages with the test sample device when the cutting element assembly is moved
to the deployed
position. The sealer further includes a motor for moving the cutting element
assembly from the
home position to the deployed position. Operation of the shoe is such that
when the cutting
element assembly is moved to the deployed position, the engagement of the shoe
with ,the test
sample device urges the test sample device against the fixed structure in the
instrument (e.g,
horizontally extending rail) to thereby hold the test sample device while the
cutting wire cuts and
seals the conduit. The fixed structure can be any suitable structure (surface,
rail, or specially
designed structure), that is positioned relative to the sealer such that when
the sealer's cutting
element is in the deployed position, the spring loaded member engages the test
sample device
and hold the device, i.e., prevent lateral movement, while the cutting wire
cuts the conduit. The
cutting action may occur by movement of the test device past the wire, in
which case the spring
loaded member permits the motion of the test device past the wire in the
direction of travel but
still holds the device against the fixed structure to prevent substantial
lateral movement
(movement perpendicular to the direction of travel of the test sample device
past the wire).
6
CA 02800042 2014-12-08
' 50621-9D1
In one particular aspect, there is provided a sealer for cutting and sealing a
conduit connecting a test sample device to a fluid receptacle containing a
fluid sample, said
sealer installed in an automated sample testing instrument, comprising: a
moveable cutting
element assembly having a home position and a deployed position, said cutting
element
assembly comprising a cutting wire and a spring-loaded member adapted for
engagement with
said test sample device when said cutting element assembly is moved to said
deployed
position, a motor for moving said cutting element assembly from said home
position to said
deployed position; and control electronics operably connected to the motor and
configured for
governing the operation of the motor so that, when said cutting element
assembly is moved to
said deployed position, the engagement of said spring-loaded member with said
test sample
device urges said test sample device against a fixed structure in said
instrument to thereby
hold said test sample device in a fixed position while said cutting wire cuts
and seals said
conduit.
In another aspect, the positioning of the cutting assembly relative to the
test
sample device and the conduit to be cut and sealed is more closely by means of
a unique
arrangement in which a single motor moves the cutting assembly in a direction
having both
vertical and horizontal components (i.e., at an angle). Changing the operation
of the motor
(such as by adjusting the motor firmware to set limits on motor travel),
adjusts the position of
the cutting element assembly in both the horizontal and vertical directions.
In particular, a
sealer for cutting and thereby sealing a conduit connecting a test sample
device to a fluid
receptacle containing a fluid sample is provided. The sealer is installed in
an automated
sample-testing instrument. The sealer includes the moveable cutting element
assembly and
the motor for moving the cutting
6a
CA 02800042 2012-12-19
50621-9D1
element assembly from the home position to the deployed position. The motor is
constructed
and arranged such that the motor drives the cutting element assembly relative
to the enclosure in
a direction having both vertical and horizontal components relative to the
instrument, whereby
adjustment of the operation of the motor results in adjustment of the position
of the cutting
element assembly relative to the instrument in both horizontal and vertical
directions.
These and other features of the sealer arrangements will be more fully
appreciated after
consideration of the following detailed description and the appended drawing
figures.
7
CA 02800042 2012-12-19
=
56621-9D1
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a perspective view of a preferred embodiment of a compact,
integrated system
for processing test samples and test sample devices. The instrument includes a
vacuum station
on the left for vacuum loading of test sample devices that are received in a
carrier, and a separate
carrier and test sample device processing subsystem on the right which
processes the carrier and
test sample devices after the test sample devices are loaded by the vacuum
station. The sealer
station is included as a module in the carrier and test device processing
subsystem.
Figure 2 is a front elevational view of the instrument of Figure 1.
Figure 3 is a top view of the instrument of Figurel.
Figure 3A is a front view of the instrument of Figure 1 with the front doors
and panels
=
open and the top panel and user access top removed.
Figure 3B is a detailed front view of the vacuum chamber with the door open
showing
placement of a loaded carrier with test sample devices and test tubes
positioned within the
vacuum chamber.
Figures 4 and 5 are diagrams of top and front views, respectively, of the
instrument of
Figure 1, showing the general location of specific sub-assemblies and sub-
systems in the
instrument; familiarity with these figures will be helpful in understanding
the more detailed
drawings in the subsequent figures, particularly Figures 16-21.
Figure 6 is an elevational view of a test sample device in the form of a multi-
well test
sample card. The instrument of Figures 1-5 is designed to process a batch of
cards of Figure 6 at
a time by means of a carrier. The carrier receives a plurality of the test
sample cards of Figure 6
and a plurality of open receptacles, e.g., test tubes, containing a fluid
sample to be tested.
8
CA 02800042 2012-12-19
50621-9D1
Figure 7 is a perspective view of a carrier loaded with test sample devices
and open
receptacles. When the test sample devices and receptacles are placed in the
carrier, each of the
test sample devices is placed in fluid communication with a sample in an open
receptacle by
means of a transfer tube, as shown.
Figure 8 is a perspective view of an empty carrier of Figure 7.
Figure 9 is another perspective view of an empty carrier of Figure 7.
Figure 10 is a top plan view of the carrier of Figure 7.
Figure 11 is a side elevational view of the carrier of Figure 7.
Figure 12 is a side elevational view of the carrier of Figure 7, opposite to
that shown in
Figure 11.
Figure 13 is an end view of the carrier of Figure 7, showing the handle.
Figure 14 is an opposite end view of the carrier of Figure 7.
Figure 15 is a bottom plan view of the carrier of Figure 7, showing the rib
and optical
interrupt positioning features formed in registry with the test sample device
receiving slots.
Figure 16 is a front perspective view of the instrument of Figure 1, with the
waste
collection and carrier loading/unloading doors removed, and with the front
user access door
removed.
Figure 17 is a perspective view of the instrument of Figures 1 and 16 with all
of the
instrument panels and doors removed, showing generally the front and left hand
sides of the
instrument, to better illustrate the subsystems and subcomponents of the
instrument, in particular
the vacuum, waste disposal, and test sample device reader subsystems.
Figure 18 is another perspective view of the instrument of Figures 1 and 16
with all of the
instrument panels and doors removed, showing generally the front and right
hand side of the
9
CA 02800042 2012-12-19
50621-9D1
instrument, in order to better illustrate the subsystems and subcomponents of
the instrument, in
particular the waste disposal, sealer, and incubation station subsystems.
Figure 19 is a top plan view of the instrument of Figures 16 and 17.
Figure 20 is a front elevational view of the instrument of Figures 16-19.
Figure 21 is a perspective view of the top of the instrument with the top
panel removed,
in order to better illustrate the various components and subsystems of the
instrument.
Figure 22 is a perspective, exploded view of the sealer station of Figure 20.
Figure 23 is another perspective, exploded view of the sealer station of
Figure 22.
Figure 24 is an assembled, perspective view of the sealer assembly.
Figure 25 is a side view of the card autoloader subassembly.
Figure 26 is a perspective view of the card autoloader subassembly of Figure
25.
Figures 27 and 28 are two perspective views showing the operation of the card
autoloader
subassembly of Figures 25 and 26 loading cards into the incubation station of
the instrument of
Figure 1.
Figure 29 is a perspective, exploded view of the transport assembly that moves
the carrier
of Figures 7-17 through the various modules or stations of the Carrier and
Test Sample Device
Processing Subsystem in the instrument of Figure 1.
Figure 30 is a top plan view of the transport assembly of Figure 29.
Figure 31 is an end view of the transport assembly of Figures 29 and 30.
Figure 32 is a detailed perspective view of the carrier-engaging block of
Figure 29-31.
Figure 33 is a view showing the movement of a loaded carrier past a detection
station
detecting the position of the carrier relative to a specific processing module
in the instrument,
here the card autoloader subassembly of Figures 25 and 26.
CA 02800042 2012-12-19
=
50621-9D1
=
Figure 34 is a detailed flow chart showing the workflow and sequence of steps
in the use
of the instrument and associated carrier, test sample receptacles and test
sample devices.
CA 02800042 2012-12-19
50621-9D1
DETAILED DESCRIPTION OF PREFERRED EMBODIMENT
The present invention relates to a sealing mechanism for sealing a transfer
tube or like
structure in a test sample device. A presently preferred embodiment of a
sealer station 400 in an
automated sample testing instrument 10 is described in conjunction with
Figures 7, 17, 18, and
22-24. In order to appreciate how the illustrated embodiment of the sealer
invention operates,
the specification will describe the invention in the context of a particular
sample testing
instrument and test sample device format. However, the invention can be
practiced in other
environments and the present description is provided by way of illustration
and not limitation.
System Overview
An overview of a compact, high throughput instrument for processing test
samples will =
now be described in conjunction with Figures 1-5. The netails on the
construction and operation
of the instrument will be described later in conjunction with Figures 6-34.
The instrument 10 processes a batch of test sample devices in the form of
multi-well test
sample cards in the illustrated embodiment. A representative test sample card
100 is shown in
Figure 6 and will be described subsequently. The cards 100 are initially
loaded in a cassette
(carrier) 200 shown in Figures 7-15. The carrier 200 further carries a set of
fluid receptacles (test
tubes) 106 (Fig. 7) that contain a fluid sample. Each test sample device 100
is placed into fluid
communication with an associated fluid receptacle 106 by means of a transfer
tube 102, shown in
Figures 6 and 7. The sample is loaded into the card by means of a vacuum
loading station in the
instrument 10 in the manner described below.
12
CA 02800042 2014-12-08
50621-9D1
The instrument 10 of Figures 1-5 is a sample processing and data collection
portion of an
overall sample testing system. The overall system includes a separate stand-
alone identification
station where bar codes on the test sample devices are scanned, the cards are
loaded into the
carrier 200, and the earlier is applied with a bar code and scanned. These
functions are similar to
the separate identification system described in the patent of Fanning et aL,
U.S. Patent 5,869,006.
The overall system further includes a workstation having a
computer processing system that receives data from the reading system in the
instrument. These
identification and computer processing aspects of the overall system are not
particularly pertinent
to the present invention and only insofar as they are relevant will they be
discussed further.
The illustrated instrument was designed as a smaller and lower-cost
alternative to more
complex sample testing instruments, such as the system described in the above-
referenced
Fanning et al. patent, for use in low to medium range applications in .both
the clinical and =
industry markets. The instrument provides for semi-automated filling, sealing,
and loading of
the test sample devices, as will be described in detail below. However,
whereas the prior art
Fanning et al. '006 patent and the Vitek 2 instrument supported automated
diluting and pipetting
functions, these functions are performed off-line by the user either manually
or using other
equipment. In other words, the user prepares the samples so that they can be
directly loaded into
the test sample devices from their associated test tube. These off-line tasks
will be discussed in
=
more detail in conjunction with the work flow chart of Figure 34.
As in the case with the Vitek 2 instrument, the instrument 10 of Figure 1-5
provides a
vacuum station 300 for inoculation of the fluid samples into the wells 104 of
the test sample card
100 Figure 6. However, in the present system the vacuum loading is performed
semi-
automatically as described herein, not fully automatically. In particular, the
user manually places
13
CA 02800042 2012-12-19
50621-9D1
the loaded carrier into the vacuum station. When the fluid samples enter the
wells 104 of the
card 100, the fluid sample rehydrates reagents previously loaded into the
wells of the card at the
time of manufacture.
After vacuum loading, the carrier 200 is then manually placed into a separate
compartment in the instrument 10 containing a carrier and test sample device
processing
subsystem 50. This subsystem 50 includes a sealing station 400 which operates
to seal the cards
by cutting the fluid transfer tube 102. The instrument 10 includes a card
autoloader sub-system
500 that automatically loads the cards 100 one at a time into an incubation
station 600. The
incubation station 600 includes a rotating carousel that holds the cards. The
cards are held at a
precisely controlled temperature. The incubation system includes a card eject
mechanism that
ejects the cards from the carousel one at a time and places the cards on a
transport assembly 700
that carries the cards to a card reader subsystem 800. The card reader
subsystem 800 includes
transmittance optics stations that perform periodic colorimetric readings of
the wells 104 of the
cards 100. A software algorithm determines changes in patterns of individual
reagent wells 104
and translates those patterns into organism identification or sets of
antimicrobial results. When
the reading is deemed complete, the cards 100 are sent by the card transport
assembly 700 to a
card disposal system 900, which holds the cards for removal from the
instrument by the user. If
further reading is required, the cards are moved back into the incubation
station 600 for further
incubation and additional reading.
A carrier transport system 1000 is provided in the instrument for moving the
loaded
carrier 200 back and forth within the interior of the carrier and test sample
device processing
subsystem. 50 of the instrument 10. The transport assembly 1000 is described
in conjunction
with Figures 29-33.
14
CA 02800042 2012-12-19
50621-9D1 =
The instrument of Figures 1-5 and 16-33 can be scaled up or down to offer
capacity for
processing 60 test sample cards at the same time, or even more. The present
discussion will
focus on an embodiment for processing six fully loaded carriers (60 test
sample devices). It will
be appreciated that by providing a larger carousel incubation station or a
second incubation
station and second optics station and associated card transport assemblies the
capacity could
double. =
The instrument 10 performs all control of sample well (test sample card)
filling and
incubation/optical reading. The instrument 10 also supports a two-step user
workflow for test
pre-processing: reagent hydration and sample inoculation (vacuum loading). The
test pre-
processing is followed by the steps performed automatically in the instrument:
cassette and test
setup verification using strategically placed bar code reader in the
instrument, card transfer tube
sealing, loading of test sample cards into the incubation station, reading of
the cards, and
unloading and return to the user of the processed carrier and test tubes. Upon
loading of the
cards 100 into the incubation system 600, the instrument controls incubation
temperature, optical
= reading, and data transfer to the workstation computer processing system
during the test
processing period. The instrument then ejects the cards upOn test
finalization, by means of
transport of the test sample cards into the card disposal system 900.
Door and User Interface Features (Figures I-3B)
Referring primarily now to Figures 1-3B, the instrument 10 includes a set of
panels 12
that cover the internal sample processing apparatus. The internal processing
apparatus is
described in more detail in Figures 16 et seq. The panels 12 include a hinged
vacuum door 302
that provides access to a vacuum chamber 304, which are part of the vacuum
loading system 300
in the instrument. The user places a fully or partially loaded cassette 200 (a
set of up to 10 test
CA 02800042 2012-12-19
50621 -9D1
sample cards 100, each connected to an associated test tube 106 via a transfer
tube 102, as shown
in Figure 7) into the vacuum chamber 304 in the manner shown in Figure 3B and
closes the
vacuum door 302. A vacuum is drawn in the chamber 304 and the release of
vacuum loads the
fluid samples into the wells of the test sample cards 100. As shown in Figure
4, the vacuum
system 300 further includes a vacuum pump assembly 306 that supplies vacuum to
the vacuum
= chamber 304.
The instrument further includes a hinged load/unload door 14. The user opens
this door
to expose a carrier loading and unloading station 16, best shown in Figure 3A,
and introduces the
carrier (loaded) into the carrier and test sample device processing subsystem
50. The loaded
carrier 200 (with the vacuum loading just complete) is placed inside the
machine at the carrier
loading station 16 for subsequent processing in the instrument (sealing,
incubation,' reading,
disposal). The transport system 1000 in the instrument engages the loaded
carrier 200 and
proceeds to move the carrier as a unit to stations in the instrument as
described in detail below.
The instrument further includes a waste access door 902 which is part of the
card disposal
system 900. The door 902 is the means by which the user gains access to a
waste compartment
904. A removable receptacle in the form of a bucket (906, Figure 16) is placed
in the waste.
compartment 904. The test sample cards are dropped into the bucket 906 after
the reading
process is complete. When the bucket is full, the bucket is removed, the cards
are discarded, and
the bucket is replaced into the waste compartment 904. =
16
CA 02800042 2012-12-19
50621-9D1
The instrument further includes a front user access door 18, a top user access
door 20,
and top service panel side and rear panels, which are not relevant to the
present discussion.
These doors provide access for periodic cleaning of the instrument or service
of components in
the instrument. Access to the interior of the instrument 10 is restricted
during processing for the
safety of the user and to ensure uninterrupted processing of the cards. The
instrument 10
monitors the status of all the doors via sensors. Doors that provide access to
moving parts, such
as the front user access door 18 and load/unload door 14, also have door locks
that are
monitored.
The vacuum door 302 and load/unload door 14 are round recessed doors. The
doors pivot
in opposite directions to provide an unobstructed transfer of the cassette 200
from the vacuum
chamber 304 to the loading station 16. A detent in the hinge for these doors
allows the door to
stay open greater than 900 until the user is ready to close it. The hinges are
recessed and hidden
from view when the doors are closed.
The instrument includes a compact user interface 22. The user interface
includes a
keypad and LCD screen, which are located on the user interface front panel, at
the top left of the
instrument 10 as shown in Figure 1. The instrument uses the screen to
communicate messages
about its operation and its status. An audible indictor is also used in
conjunction with the LCD
display to notify the user when a task is complete or if an error has
occurred. The keypad is used
to respond to instructions, send commands to the instrument, and perform other
functions.
Indicator lights located next to the Vacuum Door and Load/Unload Doors provide
additional
status information to the user.
17
CA 02800042 2014-12-08
50621-9D1
=
Test Sample Device 100 Features (Figure 6)
The illustrated embodiment is designed to process test sample devices in the
form of
multi-well test sample cards. Persons skilled in the art will appreciate that
the instrument, and its
= .constituent components, can be configured to process other types of test
sample apparatus, and
the invention is not limited to any particular forraat or design for test
sample apparatus.
A representative test sample card is shown in Figure 6. The card 100 is a
flat, thin object
having front and rear surfaces that are covered with a clear, oxygen permeable
transparent
sealing tape. The card contains 64 test sample wells 104 and an internal fluid
passage network
108 that connects each of the wells to a fluid intake port 110 and fluid
distribution manifold.. =
The fluid transfer tube 102 is automatically inserted in the fluid intake port
108 in the manner.
shown and locked in place using the teachings of O'Bear et al., U.S. Patent
6,309,890. During
vacuum loading of the card, the fluid sample 120 enters the card 100 from the
fluid transfer tube
102 and travels along the course of the internal fluid passage network 108.
The fluid sample fills
the wells 104 of the cards, where the fluid rehydrates dried reagents or
growth media. Under
conditions of incubation, a reaction occurs between the reagents in the wells
of the card and the
microorganism in the fluid sample. As a result of this reaction, the
transmittance of light though
the wells changes. The optics in the instrument 10. periodically read the
wells of the card 100 by
obtaining transmittance measurements at particular wavelengths of light
The cards for use with the illustrated embodiment are described at length in
the patent
literature and therefore a more detailed discussion is omitted. The reader is
directed to the
following U.S. Patents for further details: 5,6Q9,828; 5,746,980; 5,670,375;
5,932,177;
5,916,812; 5,951,952; 6,309,890 and 5,804,437.
18
=
CA 02800042 2012-12-19
50621-9D1
Carrier 200 Features (Figures 7-15)
Referring now to Figures 7-15, the carrier 200 or cassette is a molded plastic
component
that holds a set of test sample cards 100 and associated test tubes 106. In
the illustrated . =
embodiment, the carrier 200 holds a maximum of 10 test cards in specially
fitted slots 202. The
front portion 204 of the cassette 200 has a test tube slot 206 for each test
tube 106. The slots are
numbered 1-10 across the front of the cassette for identification purposes. A
handle 208 on the
right side allows for one-handed carrying capability. A removable bar code
label 210 is applied
to the opposite side of the carrier 200 in the flat panel portion 215 (See
Figures 7 and 14). The
bar code 210 provides cassette identification when read by a bar code reader
in the instrument
10. Each of the test sample cards is applied with a bar code 120, as shown
in Figure 7.
The user loads the carrier 200 with tubes 106 of patient isolates (or, more
generally, a
fluid sample) and test cards 100 before placing the carrier in the vacuum
chamber 304 (Figure
3A) for the filling process. The asymmetrical shape of the carrier 200 and
receiving structures in .
the vacuum chamber 304 as shown in Figure 3B ensures that the carrier 200 is
properly loaded
into the instrument (i.e., the handle 208 is towards the front of the
instrument). Upon completion
of the vacuum loading process, the user opens the door 302 to the vacuum
chamber 304 and
removes the carrier 200 from the vacuum chamber 304 and places it in the
load/unload station
16.
The carrier 200 is a main component of the transport system 1000. A special
block
feature in the transport system 1000 enables the transport system to move the
carrier through the
processing stations in the carrier and test sample device processing subsystem
50 and back to the
load/unloading station 16. Optical interrupt sensors in the transport system
detect slots 212
(Figures 8, 9 and 1 5) that are formed into the bottom of the carrier 200. The
optical intemipt
19
CA 02800042 2014-12-08
50621-9D1
sensors and the slots allow the instrument microcontroller to track the
cassette location. The
interrupt slots 212 are U-shaped voids formed in a rib 214 formed in the
bottom of the carrier
200. Each slot 212 is positioned in registry with the position of the card
directly above it.
Therefore, when the interrupt sensors detect the position of a slot 212, they
are also detecting the
position of the associated card. This feature facilitates precise carrier
positioning for automated
sealing operations and automatic loading of the cards from the carrier 200
into the entrance slot
in the incubation station.
Vacuum Station 300 Features (Figures 1-4,7, 17)
With reference to Figures 1-4 and 7, the user places a carrier 200 loaded with
test sample
cards 100 and test tubes 106, such as shown in Figure 7, into the vacuum
chamber 304 of Figure
3A and closes the door 302. The vacuum process is activated via the user
interface 22 keypad.
A silicon seal 306 on the vacuum chamber door 302 presses against the front
panel surface 308,
sealing the vacuum chamber 304. The vacuum pump in the vacuum pump assembly
306 (Figures
4, 17) starts drawing the air from the chamber 304. The air escapes from the
card channels and
wells via the transfer tubes and up through the suspension or fluid sample in
the test tubes 106.
The channels and wells inside of each card are now in a vacuum.
The vacuum station fills the card with the inoculation suspension in the test
tubes 106
using vacuum displacement principles taught in Farming et al., U.S. Patent
5,965,090.
, 20 The rate of change of the vacuum is monitored and
regulated by a pneumatic servo feedback system under microcontroller control.
CA 02800042 2012-12-19
50621 -9D 1
In particular, after a short period, the vacuum is released at a controlled
rate from the
vacuum chamber. The increasing air pressure inside the chamber forces the
suspension from
each test tube 106 through the transfer tube 102 and into the internal fluid
channels and wells
104 of the card 100. This process of course occurs simultaneously with all the
cards in the
carrier in the vacuum chamber. The result is vacuum loading of all cards 100
in the carrier 200.
The carrier 200 is now ready for insertion into the loading station 16 of
Figure 3A and
processing therein by the carrier and test device processing subsystem 50 in
the remainder of the
instrument 10.
Carrier and Test Sample Device Processing Subsystem (Figures 1, 4, 5, 16-33)
Now that the carrier 200 and test devices 100 have been processed in the
vacuum station
300, the carrier 200 is now ready for placement into the loading station 16
and processed by the
remainder of the instrument's subsystems, collectively referred to herein as
the carrier and test
sample device processing subsystem 50. This group of components includes the
transport
system 1000, sealing station 400, card autoloader subassembly 500, incubation
station 600, card
transport subsystem 700, optical reading station 800 and disposal system 900.
These features
will be described in further detail in this section.
Carrier Loading and Unloading Station 16 (Figures 1, 3A, 16)
The load/unload station 16 is where the operator manually loads the carrier of
filled cards
to start the sealing, incubation, and reading processes. The load/unload door
14 (Figure 1) will
remain locked at all times unless the user is ready to load or unload a
carrier. The door 14 is
21
CA 02800042 2012-12-19
50621-9D1
shown removed from the instrument in Figure 16 in order to better illustrate
the
loading/unloading station 16.
The loaded carrier 200 (Figures 3B, 7) is loaded into the instrument 10
through the open
load/unload station door 14. A reflective sensor 1040 (Figure 17) in the load
area is used to
sense the presence of a carrier 200 in the load/unload station 16. An
indicator light 32 above the
load/unload station 16 indicates the status of the load/unload station to the
user. Once the door 14
is closed, the processing cycle automatically initiates.
The transport system 1000 (Figures 29 ¨ 33) moves the carrier 200 by pulling
or pushing
it through each processing station within the instrument in the manner
described below. The
instrument microcontroller keeps track of where the carrier 200 is located and
the status of the
transport system utilizing the slots 212 molded into the bottom of the carrier
(described above)
and optical sensors 1050 A-C (Figure 29) that are strategically placed in the
transport system
1000. The transport system 1000 moves the carrier from the load/unload station
16 to a bar code
scanner where the carrier bar code (Figure 7) and test sample bar codes are
read, the sealer
station 400, the card autoloader station 500 where the cards are loaded into
the carousel
incubation station 600, and back to the load/unload station 16 for removal of
the carrier 200 and
the test tubes plus transfer tube 102 remnants. The carrier is parked at the
load/unload station 16,
the door 14 unlocked and the operator notified by the load/unload indicator
light 32. The carrier
200 can then be removed allowing disposal of the processed test tubes 106 and
transfer tube 102
waste, making the carrier ready for testing of the next batch of test cards
and associated fluid
samples.
22
CA 02800042 2012-12-19
50621-9D1
Bar Code Reader Station 60 (Figures 4, 5, 20, 17)
A bar code reader station 60 (Figures 4, 5) is positioned in the instrument 10
generally
below the reading station 800. The station 60 automatically scans the bar code
information on
each carrier 200 and test card within the carrier 200 (see Figure 7) as they
pass through the
station. The bar code reader station 60 consists of a bar code scanner 62
(Figure 20) and a card
sensor 1042 (Figure 17). The card sensor 1042 is located on the housing of the
incubation
assembly 600 as close to the cards in the cassette as possible. The card
sensor 1042 confirms the
presence of a card 100 in the carrier 200 and the slot location. The slots 212
in the bottom of the
carrier allow the transport system 1000 to position each card in front of the
bar code scanner 62.
As shown in Figure 7, each card 100 has a factory applied bar code 120 that
includes
information such as test type, lot number, expiration date and a unique
sequence number. When
the 'card bar codes 120 are scanned at the separate workstation at the time of
loading cards into
the carrier 200, the instrument's bar code reader 62 provides an additional
level of security by
verifying that the cards 100 are loaded as indicated by the user. If the bar
codes are not scanned
at the separate workstation ("load and go" mode), the lab technician's
worksheet can be used for
verifying that cards 100 are loaded in the carrier 200 as indicated.
Successfully scanned carriers 200 and test cards 100 are allowed to continue
to the sealer
station 400. Carriers 200 and cards 100 that cannot be read at the station 60
due to errors such
as missing or damaged bar codes, expired cards, and unsupported card types,
are returned to the
load/unload station 16 and the user notified via the user interface 22 or
indicator light 32. The
user is given the opportunity to correct the problem and reload the carrier
200 within a limited
amount of time.
23
CA 02800042 2014-12-08
50621 - 9D1
Sealer Station 400 (Figures 4, 6,7, and 17-24)
With reference to Figures 4, 6, 7, and 17-24, before a test card 100 can be
incubated and
read, the wells 104 of the test sample card must be sealed off from the
outside environment. The
sealer station 400 provides this function for all cards loaded into the
carrier 200, one'at a time.
The sealer station 400 melts and seals the transfer tube 102 using a
retractable heated nichrome
wire 402, and thereby seals the cards. This operation will now be described in
further detail.
After a carrier 200 is loaded into the instrument, a transport block in the
transport system
1000 engages with the carrier 200 and pulls the cassette 200 along the
transport system track
through a carrier sensor 1040, a card sensor 1042, and the bar code scanner
62. If the carrier
passes inspection, it is moved back along the transport system 1000 track
toward the load/unload
door 14 where the sealer station 400 operates to cut and seal all the cards in
the carrier 200. .
In particular, as the carrier 200 moves through the station 400, the hot wire
402 is
translated downwardly and at an angle through an aperture 404 in an enclosure
or housing 406 to
the same elevation of the transfer tubes 102 in the carrier 200, and thereby
exposed to each
transfer tube 102. As the carrier 200 is slowly advanced by the carrier
transport system 1000
each transfer tube is forced past the hot wire 402. The hot wire 402 causes
the plastic transfer
tube'102 to melt, separating the majority of the transfer tube, which falls
into the test tube 106.
The remainder of the transfer tube forms a short, sealed stub (e.g., 1.5 mm in
length) extending
outward from the fluid intake port 110 in the card (Figure 6). At the
completion of the sealing
processing, power is cut off to the wire 402 and it is retracted. back into
it's housing 406 to =
eliminate user contact. The temperature of the wire 402 is controlled by a
microcontroller
controlled constant current source, as described in Karl et al., U.S. Patent
5,891,396.
24
CA 02800042 2012-12-19
50621-9D1
The overall operation of the sealer to cut the transfer tubes 102 is similar
to the process
described in the Karl et al. '396 patent. As cards 100 move past the sealer,
the transfer tubes 102
are forced past the hot wire 402 melting the plastic and sealing the cards.
The wire 402 and its
associated assembly 408 then retracts into the housing 406. The carrier 200 is
then moved to the.
card autoloader station 500, which moves the cards laterally off of the
carrier 200 and into the
entrance aperture of the incubation system 600.
The sealer assembly 400 is unique in several respects: a) its method of
electronic control,
b) its mechanical alignment, c) a preloading feature where each card is biased
against fixed
structures in the instrument prior to cutting and sealing the transfer tubes,
and d) features
preventing unauthorized user access.
As for feature a), a microcontroller ensures reliable cutting and sealing by
maintaining a
constant current in the hot wire 402 while retracting or extending the wire
400 through the
aperture 404 per the card/cassette cycle requirements.
As for feature b), the sealer housing or enclosure 406 orients a wire assembly
408 and
associated drive mechanism 410 at an angle allowing alignment of the wire 402
using only one
motor 412 to control the horizontal and vertical position. The wire alignment
is achieved by
adjusting the mounting of the housing 406 in the instrument or the alignment
of the drive
mechanism 410 to the housing, and/or setting the limit positions of the motor
412 in firmware.
As for feature c) and d), the wire 402 and its associated assembly 408, and
the drive
mechanism 410 are ordinarily placed within the housing 406. A shield 416
covers the entrance
aperture 406. When a card is in position for sealing, the motor 412 is
,energized and the motor
operates to move the wire assembly 408 down and at an angle through the
aperture 406. This
action causes the shield 416 to move out of the way to a retracted position. A
spring-loaded pad
CA 02800042 2012-12-19
50621 -9D1
414 in the wire assembly 408 and located in front of the wire 402 makes
contact with the edge of
a card 100 and preloads or biases the cards 100 using a coil spring 415
against a fixed structure
or stop in the instrument. The fixed structure is in the form of a rail 604
extending lengthwise
along the face of the incubation station 600 housing 602. Other constructions
are of course
possible. The wire 402 then cuts through the transfer tube to produce uniform
stubs lengths as
the cards 100 are moved past the stationary sealer wire 402. After the sealing
operation is
completed, the motor 412 is energized to retract the wire assembly 408 into
the housing 406. As
it does so, the rotating shield 416 retracts by gravity to a closed position
covering the aperture
404. This covering of the aperture 404 prevents the user from gaining access
to the retracted hot
wire 402.
As the carrier 200 approaches the sealer station, the transport system 1000
slows its
. .
movement to a slow speed. The motor 412 in the sealer station 400 energizes to
move the wire
subassembly 408 through the aperture 404 and expose the wire 402. The pad or
"shoe" 414 is
mounted approximately 2.0 mm in front of the sealer wire 402. The shoe is
spring loaded by a
compression spring 415 shown in Figure 22. The shoe or pad 414 mounts with a
single shoulder
screw 420 and incorporates an anti-rotation feature. As the card 100
approaches the hot wire
402, the shoe 414 makes initial contact with the card, deflecting the spring
415 and preloading
the card 100 against the rail 604 (Figure 27) on the incubation assembly panel
602. This insures
consistency in transfer tube stub length. Forward motion of the carrier 200
past the hot wire 402
cuts the transfer tube 102, melting the plastic transfer tube 102 and sealing
each card. After all
the cards 100 in the carrier are sealed, the transport system 100 again
reverses direction along its
track and each of the cards is placed in registry with the card autoloader
system 500 for loading
into carousel incubation station 600 to incubate,
26
CA 02800042 2012-12-19
50621-9D1
The sealer wire 402 in the preferred embodiment is a heated 18 Gauge Chromel A
wire
mounted on a sliding block mechanism 422 inside the metal enclosure or housing
406. The
housing 406 positions the drive mechanism 410 at an angle, and locates the
extended sealer
wire/preload shoe 414 at the correct height, and prevents user access to the
sealer wire 402 and
drive mechanism. The drive mechanism 410 is mounted at an angle to simplify
the horizontal
and vertical alignment. A stepper motor 412 extends the hot wire mounting-
block 426 at a
30 angle from horizontal to simultaneously adjust the horizontal and vertical
position. This '
angle can of course vary in different embodiments and could vary for example
between 20 and
70 degrees. The exact alignment of the sealer wire 402 is adjustable by
firmware controlling the .
limits of the motor 412 to ensure a uniform stub length between 1.0 and 2.5
mm. When the
cutting and sealing operation is finished, the stepper motor 412 retracts the
hot wire assembly
408 until a flag 424 on the block 426 in the drive system is sensed by home
position sensor 428
(see Fig. 22). The assembly includes a chain 448 that serves to protect a wire
446 supplying
current to the cutting wire 402.
As the hot wire assembly 408 and mounting-block 426 is retracted, the rotating
shield
416 drops down by gravity and covers the housing opening 404. The shield 416
has a tang 430
and flange 452. The flange 452 is positioned inside the elongate opening 454
in the housing 406
when the unit is assembled. The flange 452 contacts the shoulder 426 of the
mounting-block
426 as the block 426 nears the retracted home position. The tang 430 and
flange 452 prevents
the user from lifting the shield 416 and gaining access to the hot wire. When
the sealer motor
412 is energized, it causes the pin 462 to slide through the slot 460 in the
drive mechanism 410
and thereby extends the hot wire mounting-block 422. The protective shield 406
is pushed open
by the contact between the face of the block 422, which causes the shield to
rotate upward,
27
CA 02800042 2012-12-19
50621-9D1
exposing the hot wire 402 and preload shoe 414. The microcontroller supplies a
constant
current to the wire 402 sufficient to produce the proper temperature for
cutting through the
transfer tubes as the cards pass by, melting the plastic and leaving a small
stub of the tube to seal
the interior of the card from the atmosphere.
Card Autoloader Station 500 (Figures 20 and 25-28)
Referring now to Figures 20 and 25-28, the instrument 10 further includes a
card
autoloader station 500 that loads sealed cards 100 into the incubation station
600. After the
cards have been sealed, the carrier 200 is moved to the autoloader station
500. The slots 212 in
the bottom of the carrier 200 (Figure 8) allow the transport system 1000 to
position each card
directly in front of the incubator 600 entrance slot 610, shown best in Figure
28. The slot in the
carrier is determined and tracked automatically by the instrument's internal
microcontroller.
The autoloader station 500 includes a reciprocating, motor-driven pusher
mechanism 502,
located above the carrier 200. The mechanism 502 pushes the card 100 laterally
off of the carrier
200 into the carousel (not shown) in the incubation station 600. The
incubation station 600
carousel is a circular carousel oriented on its side (rotating about a
horizontal axis) having 30 or
60 slots. One of the slots is positioned at the 6 o'clock position directly in
alignment with the
card entrance slot 610. The pusher mechanism 502 returns home and the
transport system 1000
and carousel index to the next card position. The loading of the next card in
the carrier 200
proceeds in the same fashion. Upon completion of loading all the cards, the
transport system
1000 returns the carrier 200 and test tubes 106 to the load/unload station 14
and notifies the user
via the indicator 32 and user interface 22.
28
CA 02800042 2014-12-08
=
50621-9D1
Referring now in particular to Figures 25-28, the autoloader includes a motor
504 that
drives a block 506 attached to the card pusher mechanism 502. The block 506
has internal
threads that engage a threaded shaft 510 extending laterally across the path
of the carrier 200. As
the motor 504 drives the block 506, the block 506 and attached pusher 502
slides along a guide
508. The pusher 502 contacts the cards 100 in the carrier and inserts them
automatically into the
slot 610- in the incubation station 600. The tips 512 and 514 of the shaft 510
and guide 508 are
received in apertures in a plate 612 mounted to the housing 602 of the
incubation station as
shown in Figures 27 and 28. A pair of guides 612 guide the cards 100 into the
slot 610.
Incubation station 600 (Figures 16-20)
The incubation station 600 in the instrument 10 will now be described in
conjunction
with Figures 16-20. The incubation station includes a circular carousel. The
circular carousel is
not shown in the drawings, as it is covered by a removable access cover 630
forming an
incubation enclosure. The carousel is rotated by means of a motor 632, shown
in Figure 18.
The structure and operation of the incubation station 600 and its associated
carousel is basically
the same as set forth in the patent literature, see U.S. Patents 6,024,921;
6,136,270 and
6,155,565. See also U.S. Patent
5,762,873. Accordingly, a detailed description of the construction of the
incubation station 600
is omitted for the sake of brevity.
Once the test sample cards have been sealed and the cards loaded into the
carousel via the
entrance slot 610, they remain in the carousel for the duration of the test
period (up to 18 hours)
or until the predetermined time allotment is met. The time allotment varies
for each reagent or
29
CA 02800042 2012-12-19
50621-9D1
type of card. The carousel is contained in a temperature-controlled chamber
(incubator),
enclosed by the access panel 630.
The carousel itself in a preferred embodiment is composed of four quadrants
(called
quadrocells or quads), as taught in U.S. Patent 6,136,270, together capable of
holding up to 60
test cards within the incubator. Alternative configurations are possible.
Positioning of the
carousel is accomplished by optical sensors located at the top and bottom of
the carousel, which
read positioning slots on the outside edge of the carousel. Each carousel
quadrant can be
removed independently for cleaning, However, all four carousel quads must be
in place in order
for cards to be processed.
The incubator system regulates the temperature of the cards in the carousel.
The
temperature is monitored and controlled through the use of precision
thermistors monitored by a
microcontroller maintaining at an average carousel temperature of 35.5 1 C.
Access for a
= separate user installed probe thermometer has been provided to the front
of the Incubator Cover.
This allows the user to verify the accuracy of the incubator temperature using
an independent
calibrated thermometer. The rotating carousel system delivers test cards to
the card transport
system 700, which moves the cards to the reader station 800 four times an hour
until the test is
completed. The reader head optics scans each card and returns them to the
incubator. The
carousel includes a card eject mechanism 640 shown best in Figure 18 that
ejects a card from the
12 o'clock position in the carousel and places it in a test card transport
system 700 (Figure 16)
for transfer to the optics station 800 and return to the incubation station
600. This is the same as
described in e.g., U.S. Patent 5,762,873.
= CA 02800042 2014-12-08
' 50621-9D1
Card Transport System 700 (Figure 16, 17 and 20)
As best shown in Figures 16, 17 and 20, the instrument includes a card
transport system
700 that transfers the cards from the incubation station 600 past the optical
reading station 800 '
for reading of the wells 104 in the cards 100. The card transport system 700
is essentially the
same as described in the prior U.S. patents 5,798,085; 5,853,666; and
5,888,455.
=
= Accordingly, a more detailed description is omitted for the
sake of brevity. = Basically, the card is held in a vertical attitude between
a belt 704 and a ledge
= 702 and moved from right to left and left to right by means of a
motor driving the belt 704 back -
and forth. The ledge includes a slot feature for holding cards in the vertical
position as the belt
drives the cards back and forth. As the cards are moved past the transmittance
optics heads, the
cards are moved in a precise fashion as explained below to obtain
transmittance measurements
for each of the wells in the card at a multitude of positions across the width
of the wells. The
card includes built-in alignment sensor stop holes 130 (Figure 6) to
accurately position the wells
=
in the optical system. V V V -
Reading Station 800 (Figures 4, 5, 16 and 17)
Once the cards are placed in the card transport systetn 700, they are moved
past the
=
reading station 800. The reading station includes two transmittance optics
modules .802 (see
Figures 16 and 17) that are oriented vertically, in the same direction as the
colrarins of wells in
the card. Each module 802 obtains measurements from one column of wells.
Together, the
modules 802 obtain transmittance measurements of the wells of the card in two
columns of wells
at the same time. The construction and manner of operation of the optical
reader station 800 is
essentially the same as described in the prior U.S. patents 5,798,085;
5,853,666; and 5,888,455,
31
CA 02800042 2012-12-19
50621-9D1
therefore only a general overview and discussion will be set forth herein for
sake of brevity.
Unlike these patents, the illustrated embodiment provides only transmittance
measurements, but
of course fluorescence measurements could be taken as described in these
patents by either
replacing one of the modules 802 with a fluorescence module (see U.S. Patent
5,925,884) or
adding a fluorescence module to provide three modules. Additional modules of
course could be
= provided.
The card 100 is positioned and read by the transmittance optical system
modules 802 and
returned to the carousel slot from which it was ejected. No data analysis
takes place in the -
instrument; optical data is collected and transmitted to a remote workstation
for analysis. Raw
data may be queued and transmitted to the workstation later, in the event that
communications
between the instrument and workstation is not occurring.
The reader station 800 scans each of the cards 100 once every fifteen minutes,
for four
scans per hour. Each time the card is read, it returns to the carousel to be
incubated until the next
reading cycle. After the last reading cycle is complete, the card is
transported through the optics
to the card disposal system 900 for card ejection into the waste collection
container.
The reader system 800 and card transport system 700 together performs card
positioning
and optical data collection in order to periodically monitor the growth of
organisms inside the
wells of the test cards. Optical transmittance data is used to quantify
organism growth by
measuring the optical transmittance of each well versus time. The
illustrated embodiment
currently supports two types of optics modules 802. The first module 802 has
660nm LEDs
illumination sources for each well. The other module 802 has 428nm and 568nm
LEDs for each
well. Development of a third module with additional wavelengths is of course
possible.
Each optics module 802 has 8 measurement LEDs so that it can read 8 sample
wells per
32
CA 02800042 2012-12-19
50621-9D1
column. Each card has 8 (or 16) columns of wells for a total of 64 wells per
card. Each module
802 includes not only the transmittance LED light source for each well but
also a detector for
each well that captures the LED light after passing through the well. The
detectors use silicon
photodiodes. Sampling takes place as the card, with its 8 columns of 8 sample
wells, moves
through the optical path (from LED to photodiode) of the modules 802. The
reading system
scans across each well as the card is moved by the transport system 700 in 16
spatially separated
steps, taking 3 readings per step. This data is then processed to reduce the
effect of any bubbles
that may have formed in the wells. The readings are smoothed and the peak
value is chosen.
The emitter and detector housings in the modules 802 are hinged for ease of
servicing
and access to the optics area for cleaning. This detection system is capable
of auto calibrating
internally through air for 30% to 100% transmission (no light to full light).
The optics is
calibrated to 100% transmission through air automatically before reading each
card.
Disposal System 900 (Figures 16, 17, 20)
Once incubation and optical testing of a test sample card 100 is complete, the
card is
automatically removed from the carousel in the incubation station 600, passed
through the reader
station 800, and transferred to a disposal system 900. The disposal system
includes a disposal
enclosure 904 that holds a waste container or bucket 906, and a ramp 908 that
directs the card
from the edge of the card transport system 700 into a chute 910 positioned
directly above the
waste container 906. The waste container is removable from the instrument 10
and is accessed
via the door 902 shown in Figure 1. The card is transported to the ramp 908
simply by
operating the belt in the transport system 700 to the left to carry the card
past the edge of the left-
hand ledge 702.
33 =
CA 02800042 2012-12-19
50621-9D1
The waste collection station 900 is located below the vacuum station 300 at
the front of
the instrument 10. It houses a removable waste container 906 (see Figure 16)
and a sensor (not
shown) to detect when the container is installed. The user is notified when
the waste container
906 is full or jammed. by means of the user interface 22. Software in the
instrument tracks the
number of cards added to the container after it has been emptied.
Carrier Transport system 1000 (Figures 29-33)
The instrument 10 includes a system 1000 for transporting the carrier 200 from
the
loading and unloading station 16 through the carrier and test device
processing subsystem 50.
The transport system 1000 is shown isolated in Figures 29-33 in order to
better illustrate the
components of the system. Their interrelationship with .the various modules in
the instrument 10
will be appreciated from inspection of the remaining figures, e.g., Figures
17, 19 and 20, and
from the following discussion.
Basically, the transport system 100 includes the carrier 200 and a transport
subassembly
1002 that moves the carrier 200 back and forth. The transport subassembly 1002
includes a
cassette-engaging member 1004 in the form of a block that that is adapted to
engage the carrier
in the manner described below. The transport subassembly 1002 is constructed
and arranged
such that it moves the block 1004 and the carrier 200 back and forth along a
single longitudinal
axis between the carrier loading and unloading station 16, the sealing station
400, and the
incubation loading station 500.
The transport subassembly 1002 includes a linear actuator motor 1006 that
rotates a
threaded shaft 1010. The threaded shaft 1010 is received in a threaded nut
1005 (Figure 32) that
is attached to the block 1004. A cylindrical guide member 1008 extends between
a motor/guide
34
CA 02800042 2012-12-19
=
50621-9D1
rod mount 1018 and a front bearing mount 1020. The front bearing mount 1020 is
fastened to the
base 1016 of the transport subassembly 1002 as shown in Figure 29. A pair of
lift pins 1012
extend upwards from a drive nut engagement slide 1022 through apertures 1024
in the block
1004. The lift pins are biased by springs 1026 to a lower position, such that
when the block 1004
is positioned at the loading/unloading station 14, the lower edge of the lift
pins 1012 are in
contact with a ramp or cam surface 1014 formed in the base 1016. When the
block 1004 is
moved by the motor 1006 towards the rear of the instrument, the lift pins ride
up the ramp 1014
and thereby extend through the apertures 1024. In this upper position, the
lift pins can then make
contact with features on the underneath side of the carrier 200 and thereby
pull the carrier along
the track 1030 as the motor 1 006 moves the block 1004 towards the rear of the
instrument to the
bar code reading station 60.
In operation, a reflective sensor 1040 positioned on the side of the
incubation station
housing as shown in Figure 17 detects the presence of a carrier in the loading
and unloading
station 16. As the linear actuator motor 1006 rotates the shaft 1010, the
block 1004 is moved
from the front of the instrument 10 and the two lift pins 1012 are lifted to
engage the test sample
carrier 200. The pins 1012 are lifted by means of the cam surface 1014 molded
into the base
1016 of the transport subassembly 1002. The pins 1012 are attached to the
drive nut engagement
slide 1022, which holds ball bearing wheels (not shown). The ball bearings
ride up the cam
surface 1014, lifting the pins 1012, when the motor 1006 is indexed to move
the block 1004 to
the rear of the instrument. The carrier 200 is then dragged into the
instrument past a second
reflective sensor 1042 (also shown in Figure 17), which counts the number of
test sample cards
and determines their location in the carrier. The carrier 200 and its test
sample cards are then
CA 02800042 2012-12-19
50621-9D1
presented to the bar code reader station 60, which reads the bar codes on the
test sample cards
100 and the carrier 200.
After the bar codes are read, the motor reverses and moves the carrier toward
the front of
the instrument towards the loading and unloading station 14. During the
forward travel the hot
wire in the sealing station 400 is deployed and the test sample cards are
sealed. The motor 1006
reverses again and the carrier 200 is moved to the card autoloader station 500
and placed into
position where the test sample cards can be pushed off the carrier 200 and
into the incubation
station 600.
Three optical interrupt sensors 1050A, 1050B and 1050C (Figures 29 and 30)
track the
position of the carrier 200 over the entire travel. The three sensors 1050 are
mounted to a single
printed circuit board 1052 that is snapped into the transport subassembly base
1016. The carrier
200 slides over removable and replaceable wear strips 1054. The wear strips
1054 minimize
friction between the carrier 200 and the base 1016.
As noted above, the linear actuator stepper motor 1006 moves the block 1004.
The block
1004 restrains the lift pins 1012. The motor's shaft 1010 extends nearly the
entire length of the
subassembly 1002. The end of the shaft 1010 rotates in a pillow block bearing
1020 shown best
in Figure 29. The motor end mounts into an aluminum bracket 1018. The
motor 1006 is
mounted to the bracket 1018 indirectly via four vibration control grommets and
shoulder screws.
The rotating motor 1006 drives an acme threaded nut .1005 (Figure 32) along
the length
of the shaft 1010. The nut 1005 is pressed into the aluminum block 1056, which
is coupled
indirectly to the drive block 1004 via two vibration control grommets 1058 and
shoulder screws
1060. The shoulder screws 1060 allow the nut 1005 to self align, preventing
the nut 1005 from
36
CA 02800042 2012-12-19
50621-9D1
binding with the shaft 1010. The grommets 1058 prevent noise generated by the
nut 1005 from
transmitting through the drive block 1004 and into the base 1016.
The drive block 1004 is moved horizontally by the nut 1005. When moving toward
the .
front of the instrument, a bearing surface 1060 on the block 1004 pushes the
rear surface 220
(Figure 14) of the carrier 200. When moving toward the back of the instrument,
the two lift pins
112 lift through the holes 1024 in the drive block to engage a rib 222 on the
underside of the
sample carrier (see Figure 15).
When the drive block 1004 is at the front, the block functions as a stop for a
new sample
carrier 200 being inserted into the instrument. When the drive block 1004 is
at the back of the
instrument, a reflective sensor 1064 (Figure 29) detects it and indicates to
.the instrument
microcontroller that the block 1004 is in its home position.
Three optical interrupt sensors 1050A, 1050B and 1050C are mounted to the
printed
circuit board 1052. The use of the circuit board 1052 eliminates the wires
screws required when
mounting the sensors directly to the base 1016. The sensors 1050A, 1050B and
1050C detect the
notches 212 on the underside of the carrier 200, as explained above. Each
notch corresponds to
the location of a test sample card. The sensors are located on the printed
circuit board at the card
counter reflective sensor position (sensor 1050A), the bar code reading
position (sensor 1050B),
and the incubator loading position (sensor1050C). The sensors 1050 A-C allow
the carrier's
position to be continuously monitored.
The lift pin subassembly consists of two vertical pins 1012 mounted into an
aluminum
block 1022 containing two ball bearing rollers (not shown) at the base of the
pins, functioning as
wheels. The horizontal surface 1066 the wheels roll on is stepped near the
front of the
instrument to provide the cam or ramp surface 1014, The step is angled to
allow the wheels to
37
CA 02800042 2012-12-19
50621-9D1
roll up and down, raising and lowering the pins 1012, Compression springs 1070
on the pins
between the drive block 1004 and the body of the lift pin subassembly ensure
that lift pin
subassembly drops when rolling down the cam 1014.
Rails 1072 are provided to constrain the carrier's motion to forward and
backward. The
wear strips 1054 are mounted on the left and right horizontal surfaces of the
base 1016 as shown
in Figure 29 to provide a low friction and wear surface for the carrier 200 to
slide on.
The front cover 602 of instrument incubator station 600 provides three
functions for the
transport system. Firstly, a horizontal rib 1080 (Figure 17) prevents test
sample cards from
sliding off the right side of the carrier 200 prior to insertion into the
incubation station 600.
Secondly, the reflective sensor 1040 (also Figure 17) mounted near the front
determines when
the carrier 200 is present in the loading station. Thirdly, the sensor 1042
mounted just behind the
=
sensor 1040 counts the test sample cards 100 and determines their location on
the carrier 200.
As best shown in Figures 3A and 16, the front panel of the instrument has a
tapered
entryway in the loading and unloading station 16 for loading for the carrier
200. The carrier 200
is inserted until it contacts the drive block 1014. The door 14 is closed and
the sensor 1040
registers the carrier's presence. The space between the door 14 and drive
block 1004 is such that
the reflective sensor 1040 will always detect the carrier 200 if it is present
in the loading and
unloading station.
Control Electronics and Firmware
The instrument 10 includes control electronics and firmware for controlling
the operation
of the various modules and subsystems of the instrument. The control
electronics is
conventional. Such electronics and firmware can be developed with ordinary
effort by persons
skilled in the art from the present disclosure, given the present state of the
art.
38
CA 02800042 2012-12-19
50621-9D1
=
Work Flow (Figure 34)
The work flow and processing steps for the instrument 10 will now be described
in
conjunction with Figure 34 together with the other Figures. At step 1100, the
user prepares the =
sample inoculum off line, loads the fluid samples into the test tubes, scans
the bar codes on the
cards 100, and loads the cards 100 and test tubes into the carrier (cassette)
200. The bar code
may be scanned: off line with a separate bar code scanner. The scanning steps
may be performed
at a separate identification station having a workstation or computer
programmed to receive
information regarding the samples being tested, the scans of the bar codes on
the cards being
used, and the scan of the carrier bar code. .
At step 1102, the user opens the vacuum chamber door 302 and loads the loaded
carrier
(as in Figure 7) into the vacuum chamber 304, see Figure 3A. The user then
closes the door 302
to thereby seal the chamber.
At step 1104, the user initiates the vacuum cycle filling the cards via the
user interface 22
= =
keypad. =
At step 1106, the vacuum pump is energized and a= vacuum is generated inside
the
vacuum chamber 304. The vacuum displacement fills, the cards in the carrier in
the manner
described above.
At step 1108, a test is made to see if the reagent fill was successful. The
vacuum slope
and time are monitored to insurer reagent fill.
At step 1110, if the reagent fill was not successful, the carrier processing
is aborted as
indicated at step 1112 and the user removes the carrier 200 the vacuum station
300.
39
CA 02800042 2012-12-19
50621-9D1
At step 1114, if the reagent fill was successful, the user unloads the carrier
200 from the
vacuum chamber 304.
At step 1116, the user opens the door 14 and manually places the carrier into
the loading
and unloading station 16. The detection of the carrier is made by the sensor
1040 (Figure 17).
At step 1118, the transport system 1000 moves the carrier 200 to the bar code
reader
station 60. En route, the cards 1000 loaded into the carrier are detected by
the card sensor 1042
(Figure 17).
At step 1120, the bar codes in the carrier and on the cards are 'read by the
bar code
scanner in the reader station 60. The bar codes for the carrier and the cards
are compared to the
bar codes scanned off-line (if such scanning was done).
At step 1122, the instrument determines whether the bar code read was
successful. If not,
the process proceeds to step 1124 where the transport system 1000 moves the
carrier back to the
loading/unloading station 16 and the door 14 is unlocked. At step 1126, the
user corrects errors
if possible.
If the bar code read was successful, the process proceeds to step 1128. At
this step, the
transport system moves the carrier to the sealer station 400.
At step 1130, the sealer station 400 operates to seal each of the test sample
cards in the
carrier in the manner described above. The transfer tube remnants fall into
the test tubes. =The
remaining stub seals the test sample cards.
At step 1132, a check is made to determine whether the seal of all the cards
was
successful. This is done by monitoring the hot sealer wire current, monitoring
the sealer motor
steps, and monitor the transport motor steps, and if there are no errors, the
sealer worked.
CA 02800042 2012-12-19
50621-9D1
If the sealing step was not successful, the process proceeds to step 11.42 and
the test is
aborted and the processing proceeds to step 1138.
If the sealing step was successful, the transport system 1000 moves the
carrier 200 to the
card autoloader system 500, as indicated at step 1134. The card autoloader is
described
previously.
At step 1136, the card autoloader station 500 operates to load the cards one
at a time into
the carousel in the incubation station 600. The incubator carousel may rotate
or index to any
available position to accommodate the next card.
At step 1138, after step 1136 is completed, the transport system 1000 moves
the carrier
200 with the test tubes and transfer tube remnants to the loading and
unloading station 16.
At step 1140, the user removes the carrier 200 and disposes of the test tubes
and their
= contents. The carrier is now ready for reuse.
At step 1144, the cards 100 are now housed in the incubation station 600 where
they are
incubated at a constant temperature.
At step 1146, the cards are periodically pushed out of their slot in the
carousel and placed
into the card transport system 700, where they are shuttled back and forth to
the reading system
800. The reading of all the wells in the card is designed to occur at every 15
minutes.
At step 1148, the transmittance measurements obtained by the optics modules
802 are
transmitted to the separate workstation via communications ports or interfaces
in the instrument
10.
At step 1150, a check is made to determine if the reading of the cards is
complete. This
would occur such as by whether a reaction has occurred in one or more of the
wells such that the
periodic reading of the cards indicates that identification of the sample or
susceptibility of the
41
CA 02800042 2012-12-19
50621-9D1
sample can be determined. If the test is not complete (i.e., more reading
needs to occur), the
processing proceeds to path 1152 and the card is sent back to its slot in the
carousel for more
incubation and additional reading, and steps 1144, 1146, 1148 and 1150 repeat.
If, at step 1150, the reading is complete, a check is made to see if the waste
container in
the disposal station enclosure 904 is full. If so, the user is notified at
step 1158. If not, the card
transport system 700 moves the card all the way to the left past the end of
the ledge 702 and the
card falls into the disposal system chute 910 and lands in the waste container
in the enclosure
904.
At step 1162, the user periodically empties the waste container.
Variation from the specifics of the disclosed embodiments are to be expected
depending
=
on the configuration of the test devices and other factors. The scope of the
invention is to be
determined by reference to the appended claims, in view of the above.
42
